Quick access rubber panel fastener

ABSTRACT

A fastener for attaching two panels ( 5 ) and ( 6 ) having aligned apertures consists of a fastener which utilizes a retainer ( 1 ), a through-shaft ( 2 ), a rubber sleeve ( 3 ), and an end cap ( 4 ). The shaft extends through the retainer and a rubber sleeve is fitted around the shaft being retained axially by cap ( 4 ) which is attached to the end of the shaft ( 2 ). The pre-assembled fastener is attached to a first panel ( 5 ) preferably by clinch-type attachement. Cam surfaces on the underside of a head of the shaft and inside the retainer ( 1 ) cooperate such that when the head of the shaft is turned, the shaft ( 2 ) is withdrawn from the retainer compressing the rubber sleeve ( 3 ) between the end cap and a base of the retainer ( 1 ). This causes the rubber sleeve to bulge and apply a clamp load against the backside of the second panel ( 6 ). Thus the two panels are captured between the expanded area of the rubber sleeve and the base of the retainer. A series of radial grooves in the retainer cam ramp act in concert with a protrusion on the underside of the shaft to provide multiple resting points in the rotation. The fastener provides a single, fully-assembled component which works through standard round holes in the panels to provide panel attachment in a variety of panel thicknesses that is also vibration resistant.

FIELD OF THE INVENTION

[0001] This invention relates to a fastener which enables two panels orboards to be quickly attached or disengaged. More specifically, itrelates to a fastener that provides a clamp load through the axialcompression and subsequent diametric expansion of a rubber sleeve withactuation which is achieved by rotating a central shaft less than 360degrees.

BACKGROUND OF THE INVENTION

[0002] There has long been a demand in the art for a quick access panelfastener. Quick access panel fasteners provide a fastening system tosecurely join two panels parallel to each other in a way that can bequickly and easily joined and later detached. A clamp load is also verydesirable. There are many variations of fasteners that are designed toachieve that general objective. Each has specific limitations including:cost, scope of applications, and lack of clamp load. Some require that asecond component be affixed to the mating panel by the end user or thatmultiple pieces initially must be assembled. There is a need for a quickaccess panel fastener, that provides a clamp load at low cost in aneasy-to-use single component. Several types of quick-access fastenershave been developed, none of which incorporate all of the desirableattributes.

[0003] The Camloc company offers fasteners that are sold as a singlecomponent, however they require the fastener mounting holes in bothpanels to have an odd shape that can not be drilled and can only bepunched with multiple hits or with a special punch. The fastener thenmust be aligned prior to insertion into the panels and is then turned tohold the panels together.

[0004] The Southco® company offers a Series 20 and 50 “Fractional-turnFastener” which uses a rubber sleeve with two cams and a stud. Thisfastener also has the significant drawback of the other style fasteners;namely, it must be assembled by the end user.

[0005] The Paneloc Company offers their BI-FIX quarter-turn fastenerwhich includes five components some of which are application specific toproduce a vibration resistant reusable fastener. It also requires amyriad of different components that are needed to make the fastener workin different applications.

[0006] The DZUS Company also offers a five component fastener in theirStandard Line of quarter-turn fasteners which includes a stud and agrommet that attaches to the first panel, and a spring with two rivetsthat attaches to the second panel. DZUS offers several other variations,but each includes multiple, unassembled components.

[0007] While there are many variations of quick-access or quarter-turnfasteners available that solve a myriad of problems, each variant hasassociated with it a number of drawbacks. The present invention comes asa pre-assembled, single piece fastener which can be rigidly attached tothe first panel by well known methods including clinching, flaring, andthe like. For this reason, it is excellent from a DFMA (Design ForManufacturing and Assembly) standpoint. Thus, the present inventionsolves many problems unaddressed by the prior art.

SUMMARY OF THE INVENTION

[0008] In order to address the problems of the prior art, the presentinvention consists of a fastener which incorporates a top side retainer,a through shaft, a rubber sleeve, and an end cap. The retainer includesa radially disposed cam ramp that cooperates with a mating cam ramp onthe underside of the head of a shaft. A clamp shaft extends through theretainer and a rubber sleeve is fitted around the clamp shaft which isretained axially by a cap which is attached to the end of the shaft. Thefastener assembly, consisting of the shaft, retainer, rubber sleeve andend cap, is attached to a first panel preferably by a clinch typeattachment, with the rubber sleeve extending through the second panel.When the head of the shaft is turned by a tool, the cam-action betweenthe head and the retainer withdraws the shaft axially from the retainer,compressing the rubber sleeve between the end cap and the base of theretainer. The rubber sleeve bulges under compression and thereby appliesa clamp load against the backside of the second panel. Thus, the twopanels are captured between the expanded area of the rubber sleeve andthe base of the retainer. During the rotation of the shaft, a series ofradial grooves in the retainer cam ramp act in concert with a singleradial protrusion on the underside of the mating cam ramp of the shaftand provide multiple detents or resting points in the rotation. The useof multiple detents allows for additional panel thickness variation andgreatly improves its performance by controlling the amount of clampforce.

[0009] The present invention provides many advantages over the priorart. It provides a clamp load in a variety of sheet thicknesses.Furthermore: it is inexpensive, it is a single fully-assembledcomponent, it works with a standard round hole, it can be permanentlyaffixed to a panel, and it is vibration resistant.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a side view of the present invention holding two panelstogether.

[0011]FIG. 2 is a top, left isometric view of the assembled inventionshown in FIG. 1.

[0012]FIG. 3 is an assembly view showing various parts of the presentinvention installed into two panels.

[0013]FIG. 4 is a top, right front isometric assembly view of thepresent invention installed into two panels.

[0014]FIG. 5 is a side view of the present invention tightened downapplying a clamp load to the panels.

[0015]FIG. 6 is a bottom, right rear isometric view of the shaft elementof the present invention.

[0016]FIG. 7 is a front view of the shaft element of the presentinvention.

[0017]FIG. 8 is a top view of the retainer element of the presentinvention.

[0018]FIG. 9 is a side view of the retainer portion of the presentinvention.

[0019]FIG. 10 is a top, right isometric view of the retainer portion ofthe present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0020]FIGS. 1 and 2 show the panels in a unfastened condition with panel5 located in position against the base of the retainer 1. The shaft isseated at the lowest possible point in the retainer 1, allowing therubber sleeve 3 to be in a relaxed, unstressed state. The pre-assembledfastener may be permanently attached to the top panel 5 through means ofa clinch, adhesive or another similar method such as clinch 8 shown inFIG. 9. The bottom panel 6 is loose and in this state the fastener andtop panel could be freely removed away from the bottom panel 6. Theround hole is the only feature required on the bottom panel 6. The shaftincludes an actuation device, shown as slot 7, but could it be a hex(internal or external) wing, knurl, handle or another similar drivefeature.

[0021] As the shaft is turned, the underside of the head forces theshaft outward from a mouth of the retainer do to the camming action ofthe cooperating ramps on the underside of the head and the inside of theretainer. This causes the rubber sleeve 3 to be compressed between theend cap and the base of the retainer, thus expanding its diameter andforcing the expanded area against the backside of the second panel. Inthis manner a clamp load is achieved as shown in FIG. 5. The end cap 4that holds the rubber sleeve 3 in place may be attached to the shaft 2by a variety of means. Shown is a press fit 11 which simply provides aninterference fit with a property sized hole in the end cap 4.

[0022] Referring now to FIGS. 3 and 4, the present fastener is afour-piece assembly comprised of the retainer 1, the shaft 2, the rubbersleeve 3 and the end cap 4. The shaft 2 seats in the retainer 1 so thatturning the shaft 2 ramps it upwards on the retainer 1. The rubbersleeve 3 sits on the shaft 2 and is held in place by the end cap 4. Theend cap 4 is permanently attached to the shaft 2 through a clinch, pressfit, or another similar method.

[0023] Referring now to FIGS. 6 and 7, the shaft element of the presentinvention is shown in isolation. The shaft includes a barrel-shaped headhaving drive means 7. The underside of the head includes a cam ramp 9 athat includes a detent 10 which protrudes from the ramp. At the end ofthe shaft is a press fit stub 11. FIG. 7 shows the same elements butfrom a side view perspective.

[0024]FIGS. 8, 9 and 10 all detail the retainer component. FIG. 8 showsthe retainer 1 from the top. The series of grooves 12 can be seenradiating outward from the through hole 13. The grooves 12 are arrangedon the ramp 9 b of the retainer 1 so that they hold the detent (element10 of FIGS. 6 and 7) while the rubber sleeve 3 is compressed. FIG. 9 isa side view that again shows how the grooves 12 are arranged on the ramp9 b. It also shows a clinch 8, which is the preferred means topermanently attach the fastener to the top panel.

[0025] Thus, the objects of the present invention have been achieved.The fastener disclosed herein is sold as a single, fully assembled partthat is easy to use, requiring no assembly. Furthermore, the fastenercan be permanently affixed to a panel so that there are no loose partsin either the locked or unlocked state and it installs into two,easily-formed round holes with no special tooling required to preparethe holes. The holes are simply punched or drilled quickly and withstandard tooling. Because the rubber is in compression while in use, thefastener will always generate a clamp load. Also, the amount of finalclamp load is adjustable by how far the shaft is turned.

[0026] It should be understood that there may be other modifications andchanges to the present invention that will be obvious to those of skillin the art from the foregoing description, however, the presentinvention should be limited only by the following claims and their legalequivalents.

What is claimed is:
 1. A fastener for attaching two panels havingaligned apertures, comprising: an elongate retainer having alongitudinal axial bore, a base at one end, and a mouth at an oppositeend; a first cam integral with said retainer, said cam radially disposedaround the mouth of said retainer and extending longitudinallytherefrom; a shaft having a head at one end and a shaft, said shaftextending through said bore and beyond the base of said retainer; asecond cam in frictional engagement with said first cam, said second camextending longitudinally from an underside of said head of said shaft;an elastomeric sleeve located around a portion of said shaft whichextends beyond the base of said retainer, said sleeve having an outsidediameter greater than said bore and being in axial abutment with saidbase; and a cap affixed to a second end of said shaft, said cap being inabutment with the sleeve whereby rotation of said shaft causesretraction of said shaft from the mouth of the retainer and bulging ofsaid elastomeric sleeve such that when said fastener is installedthrough aligned apertures in a first panel and a second panel, a bulgecreated by turning the shaft applies an axial clamp force against anopposite side of the second panel.
 2. The fastener of claim 1 whereinsaid base further includes attachment means for fastening the retainerto the first panel.
 3. The fastener of claim 1 wherein said first camincludes a plurality of radially-extending grooves and said second camincludes a longitudinally protruding detent whereby said pin isselectively held at different positions when said detent lies within agroove.
 4. The fastener of claim 2 wherein said retainer base attachmentmeans affixes said fastener to the periphery of an aperture in the firstpanel.
 5. The fastener of claim 4 wherein said retainer attachment meansare clinch structures which receive the deformation of material from thefirst panel.
 6. The fastener of claim 1 wherein said elastomeric sleeveis composed of rubber.
 7. An assembly of parts, comprising: a firstpanel in face-to-face abutment with a second panel, each panel includingat least one aperture aligned with at least one aperture of the otherpanel. a fastener installed through said aligned apertures in bothpanels forceably clamping said two panels together, said fastenercomprising: an elongate retainer having a longitudinal axial bore, abase at one end, and a mouth at an opposite end; a first cam integralwith said retainer, said cam radially disposed around the mouth of saidretainer and extending longitudinally therefrom; a shaft having a headat one end and a shaft, said shaft extending through said bore andbeyond the base of said retainer; a second cam in frictional engagementwith said first cam, said second cam extending longitudinally from anunderside of said head of said pin; an elastomeric sleeve located arounda portion of said shaft which extends beyond the base of said retainer,said sleeve having an outside diameter greater than said bore and beingat axial abutment with said base; and a cap affixed to a second end ofsaid pin, said cap being in abutment with the sleeve whereby rotation ofsaid shaft causes the retraction of said shaft from the mouth of theretainer and bulging of said elastomeric sleeve such that when saidfastener is installed through aligned apertures in a first panel and asecond panel, a bulge created by turning the shaft applies an axialclamp force against an opposite side of the second panel.
 8. Theassembly of claim 7 wherein said first cam includes a plurality ofradially-extending grooves and said second cam includes a longitudinallyprotruding detent whereby said shaft is selectively held at differentpositions when said detent lies within a groove.
 9. The assembly ofclaim 7 wherein said retainer base attachment means affixes saidfastener to the periphery of the aperture in the first panel.
 10. Theassembly of claim 9 wherein said retainer attachment means are clinchstructures which receive the deformation of material from the firstpanel.
 11. The assembly of claim 7 wherein said elastomeric sleeve iscomposed of rubber.
 12. The assembly of claim 10 wherein said panels arecomposed of metal.
 13. The fastener of claim 1 further including toolengagement means on the head of said shaft.
 14. The assembly of claim 7wherein said base further includes attachment means for fastening theretainer to the first panel.